1. Field of the Invention
This invention relates to an information retrieval apparatus and an interface for information retrieval for use in a data base system, a file system, and a dictionary retrieval system. More specifically, this invention relates to an information retrieval apparatus and an information retrieval interface for handling requests for retrieving two-dimensional information such as maps, drawings of facilities, electric circuit diagrams, and chemical constitutional formulas.
2. Description of the Related Art
When information retrieval requests are entered in a data base storing image information such as drawings of facilities, electric circuit diagrams, and medical diagnostic drawings, such requests are made not only by the file name of a drawing or diagram but also by specifying the name of an element contained in a given drawing or the spatial arrangement of several such elements. For example, in the case of electric circuit diagrams, a request is made for retrieving a circuit diagram including a circuit in which a two-input NAND symbol and a three-input OR symbol are positioned at "A" in the diagram and interconnected in a relation like "B". In the case of maps, for example, a request is made for retrieving a house in which its name is "A", a "national route" and a "local route" run in its neighborhood, they intersect like "B", there is a park and a hospital at a distance of approximately "D" from the routes in the direction of "C", and it is in a positional relation of "E" with respect to these elements.
Conventionally, such retrieval is performed on the basis of a request using a command in general language form or a relational query language of a Special list form (refer to NING SAN CHANG and KING SUN FU: "Query-by-Pictorial-Example" IEEE Transaction on Software Engineering, vol. SE-6, No. 6, pp 519-524, November 1980.) This special type of retrieval language is designed on the basis of an analysis of retrieval requests which are expected to be made. However, in the method of entering retrieval requests in accordance with the retrieval languages having one-dimensional representation system, users must enter in detail a spatial and topological positional relationship between elements in accordance with many retrieval languages, in order to represent a two-dimensional positional relationship between plural elements forming image information. Thus, many data entries become needed for a retrieval request, degrading the processing efficiency. Moreover, the retrieval language itself is complicated. Therefore, the conventional retrieval-request entry method is difficult to use.